IMPURE AIR

Rotorua Morning Post, Volume 2, Issue 260, 25 June 1932, Page 8

IMPURE AIR

RAVAGES ON LONDON I BUILDINGS CAUSE | GREAT EXPENSE. 1 LESSONS FROM STONES. I During the past twenty-five years 1 a total of about £60,000,000 has been g spent in Britain in repairs to publie buildings made necessary hy the decay | of stonework caused hy atmospherie | impurities, says the London Daily * Telegraph. | The prevention of reduction of this | enormous wastage is the subject of a * report issued by the Department of | Scientific and Industrial Research. It ; embodies the results of investigations > carried out hy the Building Research Station during the past six years un- j der Mr. R. J. Schaffer, and presents the conclusion that no specific preser- t vative of stonework can yet be re- | commended. j Various suggestions are, however, j put f orward for reducing the progress | of destruction. One is that tbe best , cosmetic for the face of our cities is j ■water. Regular washing removes the salts which are largely responsible for decay. Lessons from stones of some of the . | older puhlic buildings are embodied in | the report. For instance, the wrong choice of stone for the style of archi-. tecture concerned is exemplified in the Houses of Parliament. Unsuitable Material. "The dangerous condition of the Anston stone in the Houses of Parliament," the report states, "is due to the use of a vented stone for a highly

decorated huildmg, and it is principally in the decorative and free stand- g ing features that restoration has be- | come necessary. _ S "The museum of Practical Geology | in Jermyn Street was built of Anston | stone at about the same time as the j| Houses of Parliament, but in classic | style, with plain wall surfaces. Hence, | the opening of the vents (minute fis- g sures in the stone) has had no seri- 0 ous consequences." | The Royal Commission which select- | ed the stone for the construction of | the Houses of Parliament could not | be blamed for the failure. The de- | sign had already been approved, and ® the Commissioners were required to | select a stone which would be durable | in the London atmosphere and which | could also be freely carved. g Examples of Failure. ^ "The Houses of Parliament _pro- | vide an outstanding example of failure g resulting from the unsuitability of | the material to the design." it is stated. "It may he recalled that an offer to supply free of charge sufficient granite to build the Houses of Parliament had to he rejected owing to the difficulty of working the stone to the accepted design. Then there is the damage caused hy the improper use of iron in stonework, of which St. Paul's furnishes examples. The results might have been different if Wren's instructions that no iron should be used within 9 inehes of the air had been carried out, but his command was not obeyed. Uver 1000 iron cramps and dowels jj were removed from the main piers of : the cathedral during the recent re- l pairs. Many of these, which had j caused much damage to the masonry, ; were found to lie within an inch or I two of the surfaee of the stone. j The brick core and peristyle of St. .j Paul's Cathedral were reinforeed with . massive iron chains, and much trouble ; had been caused by the effects of cor- j rosion. Further damage to the build- ? ing had resulted from the later intro- ; duction of iron reinforcements. \ The Tower of London furnished a | curious instance of the unexpected. | "Some of the best-preserved stone- | work in ancient buildings," says the | report, "is to he found in arches and | doorways exposed to contact with the r hands and clothing of passers-by. A good example is the Byward Tower of the Tower of London, where for many years guides have traced with their fingers a monogram carved in the stone. Attempts have heen made to secure a similar effect by treating stone with lanoline."